Method of making a trim strip

ABSTRACT

The disclosure relates to a method of making a trim strip comprising the extrusion of a vinyl material to form a body which is so shaped that it can be confined in a peripheral slot in a roll, thereby to permit substantial pressure to be applied on the extruded body and a decorative strip by a mating roll. The top portion of the extruded body has side extensions which are supported by the edges of the recessed roll; thus, substantial pressure can be applied on the entire top of the decorative surface strip and the body to produce an adhesive bond or a bond by heat sealing. After the body is cooled, it is advanced through a number of aligned milling cutters to machine aligned recesses in the sides of the body to produce a retention cutout. After being machined to depth, the trim strip is advanced through a pair of grinding wheels to accurately form and space the recesses. During the extruding operation, a coated wire may be embedded within the body in the conventional manner.

This is a continuation of application Ser. No. 690,027, filed May 26,1976, abandoned.

BACKGROUND OF THE INVENTION

Difficulty has been experienced in producing a decorative trim stripwith undercut recesses in the sides of the extruded body thereof due tothe limited amount of pressure which can be applied to such a decorativestrip incident to bonding of the top surface thereof to the extrudedbody. One manner of producing such a decorative trim strip was toprovide two extruded strips which are joined together after thedecorative strip is applied by a substantial pressure to the surface ofthe top extruded strip. Thereafter, it was necessary to bond the twoextruded strips together, all of which resulted in an increase in timeand cost.

SUMMARY OF THE INVENTION

The invention pertains to the method of producing a decorative trimstrip having aligned recesses in the sides of the body portion thereofby which it is secured in position. The difficulty in producing thestrip is caused by the substantial pressure required to secure adecorative surface on the body portion thereof. In the presentarrangement, the decorative strip has a body which is provided withsides which may be parallel or slightly convergent below a top portionwhich is to be decorated. The body has side extensions extendinglaterally beyond the straight sides of the body. The extruded bodyportion of the decorative trim strip is advanced between a pair ofrolls, one roll having a recess which accurately receives the bodyportion of the extruded strip with side portions of the roll engagingthe underside of the lateral extensions on the extruded element. The topof the body portions of the trip strip has, in the disclosed exemplarlyembodiment, an arcuate surface. A second roll has a recess the shape ofthe top portion of the extruded body.

The body and a decorative top surface are advanced through the rollswhich, along with the heat of the extruded material, produces a bondingof the decorative surface to the top surface of the body portion of theextrusion. Substantial pressure can be applied since all portions of theextruded material and decorative surface are confined and supported.Since undercut recesses are to be provided in the body below the topportion, the decorative extruded strip, when cooled, is advanced throughsets of aligned milling cutters which cut the straight sides of the bodyto a predetermined depth until a desired depth for the recesses isreached. The decorative extruded strip may be further advanced through aset of aligned grinding wheels to accurately grind the recesses to exactsize and shape.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an enlarged sectional view of a finished decorative trim stripwhich is produced by the method of the present invention, including theuse of aligned grinding wheels for finishing machined recesses to size;

FIG. 2 is a view of a pair of rolls which confine the extruded elementwhen substantial pressure is employed to secure a decorative surface tothe top surface of the extruded element;

FIG. 3 is a broken view of the extruded body and adherred decorativesurface when cooled and advanced through a pair of aligned millingcutters for partially machining side recesses therein; and

FIG. 4 is a broken view of the extruded body and adherred decorativesurface similar to that illustrated in FIG. 3 being advanced between asecond pair of aligned milling cutters which machine the side recessesto depth.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A decorative trim strip 11, as illustrated in FIG. 1, comprises anextruded body portion 12 and a decorative top surface 17 which isadhesively bonded or heat sealed under pressure to the extruded body 12.The body 12 is extruded in the conventional manner from any formableheated material which is known to be suitable, for one herein employedbeing a plasticized black vinyl composition. As illustrated in FIG. 2,the body portion 12 has a lower portion 14 with straight sides 15 whichmay be parallel or slightly convergent and a bottom 16 of flat, arcuateor other shape, as desired. The body portion 12 has laterally extendingedges 13 for support of the edges of the decorative surface 17.

In the disclosed embodiment, the decorative surface 17 has an innertransparent layer 18 and an outer transparent layer 19. The innertransparent layer 18 is a thin film of polyethylene terephthalate,commonly known as Mylar, which is provided with a metallic coating 21applied by vapor deposition of a metal, such as aluminum, on theundersurace of the clear Mylar film which permits the metal coating tobe visible therethrough. The Mylr film has its outer surface secured tothe undersurface of the vinyl strip 19 by an adhesive bond or by a heatsealing. The outer layer 19 is clear to permit the metal to be visibletherethrough. The outer layer 19 has, for example, a hardness of between95 to 99 Durometer as measured on the Shore A scale, 15 second delay atambient temperature. Obviously, other decorative surfaces can beemployed within the concept of the invention.

If desired, during the extruding operation, a wire 22 having a suitablecoating thereon, can be imbedded within the vinyl body 12 in theconventional manner. The trim strip 11 as herein illustrated issubstantially enlarged. In reality, the width at the top edges 13 of thestrip is approximately 1/2 inch, while the depth and width of the bodyportion 12 is approximately 1/3 of an inch.

A pair of rolls 23 and 24 support the extruded lower body portion 14 andthe decorative surface 17 as they pass therethrough to secure the twoportions together. The lower portion 14 is supported within the recess25 of the roll 23 with the straight sides 15 in engagement with theinner surface of the side elements 26 and the bottom arcuate shape 16with arcuate surface of the inner portion 27 of the roll recess 25. Thetop edge 28 of the side elements 26 engages the underside of the sideextensions 29 of the top portion 13 which has an outer surface ofarcuate shape.

The outer roll 24 has an arcuate recess 31 which conforms to the shapeof the decorative strip 11. The extruded body portion 12 and decorativesurface 17 are thus confined in the recesses 25 and 31 of the rolls 23and 24 which are so formed as to apply substantial pressure to thesurface 17 and body 12 when advanced between the rolls.

This substantial pressure produces the adhesive bond or heat sealing ofthe decorative and protective surface 17 to the body portion 12. The twoportions of the trim strip 11 are bonded together over the entireengaged surfaces and are sufficiently flexible to permit the resultingdecorative strip 11 to be bent at a comparatively small angle.

The trim strp 11, so produced, is permitted to cool and thereafter isadvanced through cutting and grinding wheels to produce recesses 36 inthe sides 15 thereof.

As illustrated in FIGS. 3 and 4, the decorative strip 11 is advancedthrough a plurality of milling cutters, two pairs being employed. Thefirst pair 32 are aligned, the teeth 33 thereof cutting into the sides15 of the lower portion 14 of the extruded body 12 after which the strip11 is advanced to a second pair of aligned milling cutters 34 havingteeth 35 thereon which cut the recesses 36 to proper depth. Furtheradvancement of the decorative strip 11 moves it past a pair of alignedgrindng wheels 37, as illustrated in FIG. 1, which shape the recesses 36to exact form so that the trim strip can be readily secured incomplimentary retaining clips. It is to be understood that if a shapeother than the arcuate shape 16 is provided for the bottom of the lowerportion 14 of the extruded body 12, the central portion 27 of the roll23 will be provided with the same shape so as to prevent deflection ofthe material of the body 12 when pressure is applied by the roll 24 tothe decorative surface 17 being bonded thereto.

While it will be apparent that the invention herein disclosed is wellcalculated to achieve the benefits and advantages as hereinabove setforth, it will be appreciated that the invention is susceptible tomodification, variation and change without departing from the spiritthereof.

What is claimed is:
 1. The method of producing a continuous decorativetrim strip which includes the steps of: extruding a plastic material toproduce a continuous flexible body with a lower portion havingsubstantially parallel sides and a top portion having a laterallyextending flange at each side edge extending above and laterally beyondthe parallel sides, advancing said continuous flexible body and adecorative strip between bottom and top rollers which closely confinesaid body and decorative strip for securing the body and strip togetherunder pressure, supporting all portions of said flexible body againstmovement in the direction of pressure application by said rollers, andadvancing the strip from the rollers to have the parallel sides on thelower portion of said body pass between a pair of spaced milling cuttersto produce inwardly extending recesses below the flanges and into theparallel sides of the lower body portion to facilitate retention of saidflexible trim strip.
 2. The method of producing a decorative trim stripas recited in claim 1, wherein the strip is further advanced to passbetween a second pair of spaced milling cutters to deepen said recesses.3. The method of producing a decorative trim strip as recited in claim1, wherein the strip is further advanced to pass between a pair ofspaced grinding wheels to finally form and smooth said recesses.